1. The Field of the Invention
The present invention relates generally to an apparatus for catheterizing a body cavity, and is particularly directed to a balloon catheter with a distally distending balloon which envelops the catheter tip upon inflation.
2. Description of The Related Art and Background of the Invention
Catheterizing a body cavity can be advantageous in many instances such as to insert or remove fluids to or from the cavity. It is also known to be desirable to use a device such as an inflated balloon near the tip of the catheter to hold it in the body cavity. This type of balloon is fashioned around the perimeter of the catheter shaft such that when it is deflated, it adds little to the overall diameter of the catheter. When the catheter tip is inside the body cavity, the balloon is inflated and thereby precludes withdrawal of the portion of the catheter distal to and covered by the balloon. Examples of cavities often catheterized in this manner are the stomach or an intestine. Examples of the function of such catheterization are fluid drainage and bolus feeding.
Attachment of the balloon to the catheter shaft is commonly accomplished by gluing proximal and distal cuffs to corresponding positions on the external surface of the catheter shaft. Such balloon cuffs are longitudinal sections of the balloon whose inside diameter correspond to the outside diameter of the shaft at positions near the distal tip of the catheter and have a distance between which is roughly the length of the uninflated balloon from the distal tip. It will be appreciated that the size of the catheter and the uninflated length of the balloon will vary in accordance with the size and shape of the body cavity and the nature of the matter to be moved through the catheter. The glue cuffs must be of sufficient length to provide a tight and durable seal between the balloon and the catheter shaft.
As the uninflated balloon is inherently elastic, the catheter shaft must be rigid enough to withstand insertion pressures. This is especially true at the distal catheter tip of the shaft.
The volume and internal geometry of hollow internal body organs is often dynamic. A clear example of this is the stomach. Opposing internal surfaces and folds regularly come into contact with each other. This is especially true when the cavity is empty and the animal is physically active. The presence of a stiff catheter tip in this environment has been suspected of irritating the opposing surfaces of the body cavity.
Accordingly, there is a need in the art for a balloon catheter with a stiff distal tip isolated from opposing internal body cavity surfaces.